JP4650336B2 - Projector and projector manufacturing method - Google Patents

Description

  The present invention relates to a projector and a method for manufacturing the projector.

  Conventionally, a projector including a first lens array, a second lens array, and a superimposing lens as a light uniformizing optical system is known (for example, see Patent Document 1). According to the conventional projector, the light with a relatively non-uniform in-plane light intensity distribution emitted from the light source device is obtained by the functions of the first lens array, the second lens array, and the superimposing lens as a light uniformizing optical system. Since the light is converted into light having a relatively uniform internal light intensity distribution, image formation in a liquid crystal device as an electro-optic modulation device to be illuminated by such light having a relatively uniform in-plane light intensity distribution The area can be illuminated.

JP-A-8-304739 (FIG. 11)

  However, the conventional projector has the following two problems.

1. First problem In a projector, if the image forming area of the electro-optic modulation device cannot be accurately illuminated, the brightness of the projected image projected on the projection surface may be reduced, or the edges of the projected image may be shaded. I'll be relaxed. Therefore, in consideration of the dimensional error and mounting accuracy of the optical element itself in the illumination optical system and the color separation light guide optical system, the illumination area of the illumination light irradiated on the image forming area has a certain illumination margin around it. Is provided. The design is performed so that the image forming area of the electro-optic modulator is surely within the illumination area including the illumination margin.

  By the way, the amount of such an illumination margin is preferably as small as possible. This is because if the size of the illumination area including the illumination margin becomes larger than necessary with respect to the image forming area, the illuminance in the image forming area decreases accordingly, and the brightness of the projected image projected on the projection surface is reduced. It is because it falls. In order to match the illumination area with the image forming area by reducing the amount of the illumination margin as much as possible, it is necessary to adjust the size of the illumination area.

  In adjusting the size of the illumination area, conventionally, for example, the size of the illumination area is adjusted by adjusting the position of each optical element (for example, the first lens array, the second lens array, and the superimposing lens) in the illumination optical system. However, such work requires a lot of labor and work time. For this reason, according to the conventional projector, there is a problem that it is not easy to adjust the size of the illumination area.

2. Second Problem In recent years, there has been an increasing demand for miniaturizing electro-optic modulation devices in order to reduce the cost of projectors. When the electro-optic modulation device is downsized, the size of the image forming area is also reduced. Therefore, it is necessary to reduce the size of the illumination area in accordance with the size of the image forming area.

Here, the size of the illumination area is the ratio of the focal length f ₂ of the superimposing lens to the focal length f ₁ of the second small lens of the second lens array (== the size of the first small lens of the first lens array). f ₂ / f ₁ (magnification rate)). Therefore, in order to reduce the size of the illumination area, the size of the first small lens is reduced, the focal length f ₂ of the superimposing lens is shortened, or the focal length f ₁ of the second small lens is increased. Must.

However, in order to reduce the size of the first small lens, the size of each small lens must be changed to the first lens array, and in order to shorten the focal length f ₂ of the superimposing lens. The size of the color separation light guide optical system must be reduced, and in order to increase the focal length f ₁ of the second small lens, the size of the illumination optical system must be increased. That is, in order to reduce the size of the illumination area, the illumination optical system (including the first lens array) or the color separation light guide optical system must be changed.

For this reason, according to the conventional projector, there is a problem that the illumination optical system or the color separation light guide optical system before the change of the electro-optic modulation device cannot be used by downsizing the electro-optic modulation device. .
This problem is not only caused when the electro-optic modulation device is downsized but also occurs when the electro-optic modulation device is enlarged.

  That is, according to the conventional projector, there is a problem that the illumination optical system or the color separation light guide optical system before the electro-optic modulation device change cannot be used as it is by changing the size of the electro-optic modulation device. It was. As a result, the illumination optical system or the color separation light guide optical system has to be redesigned, which increases the man-hours for the design and increases the manufacturing cost of the projector.

  Therefore, the present invention has been made to solve at least one of the first problem and the second problem described above, and a projector that can easily adjust the size of the illumination area, or It is an object of the present invention to provide a projector that can use the illumination optical system or the color separation light guiding optical system as it is before the electro-optic modulator is changed even if the size of the electro-optic modulator is changed. Another object of the present invention is to provide a method for manufacturing such an excellent projector.

  The projector of the present invention includes a light source device that emits an illumination light beam, a first lens array that includes a plurality of first small lenses that divide the illumination light beam from the light source device into a plurality of partial light beams, and the plurality of first small light beams. A second lens array having a plurality of second small lenses corresponding to the lens, a superimposing lens that superimposes each partial light beam from the second lens array on an illuminated area, and an image of light superimposed by the superimposing lens In a projector including an electro-optic modulator that modulates according to information and a projection optical system that projects light modulated by the electro-optic modulator, the projector is disposed in an optical path between the superimposing lens and the electro-optic modulator. An optical lens, and the optical lens has a focal length different from the focal length of the superimposing lens and has a focal position substantially the same as the focal position of the superimposing lens. Characterized in that configured with the superimposing lens superimposing optical system having a.

For this reason, according to the projector of the present invention, the focal length is substantially the same as the focal position when the superimposing optical system is configured with only the superimposing lens, and is different from the focal length when the superimposing optical system is configured with only the superimposing lens. The superimposing optical system can be configured with a superimposing lens and an optical lens, so that the superimposing optical system has a function capable of changing the size of the illumination area without changing the imaging position of the illumination area. It can be. That is, by placing an optical lens that constitutes a superimposing optical system having a focal length different from the focal length of the superimposing lens at a predetermined position in the optical path, the focal point of the superimposing optical system composed of the superimposing lens and the optical lens is arranged. The size of the illumination area can be adjusted by adjusting the distance.
At this time, the size of the illumination area is the ratio of the focal length f ₃ of the superimposing optical system to the focal length f ₁ of the second small lens of the second lens array ( = F ₃ / f ₁ (enlargement ratio)), the projector according to the present invention arranges an appropriate optical lens in the optical path and fixes it by the optical lens fixing device, thereby providing an illumination area Can be adjusted to an appropriate size.

  In addition, according to the projector of the present invention, the focal position of the superimposing optical system composed only of the superimposing lens when the optical lens is not disposed in the optical path, and the superimposing lens and the optical lens when the optical lens is disposed in the optical path. Therefore, even if the optical lens is arranged in the optical path, the in-plane light intensity distribution without defocusing in the image forming area of each electro-optic modulation device can be obtained. The relatively uniform illumination light is irradiated.

  Further, according to the projector of the present invention, the size of the illumination area can be adjusted with a very simple configuration in which the optical lens is arranged in the optical path.

  On the other hand, even when the size of the electro-optic modulation device is changed, for the same reason as described above, according to the projector of the present invention, when arranged in the optical path, the focal length is different from the focal length of the superimposing lens. An optical lens that constitutes the superimposing optical system can be arranged in the optical path, and the focal length of the superimposing optical system composed of the superimposing lens and the optical lens can be adjusted, and as a result, the size of the illumination area is adjusted. be able to.

Further, according to the projector of the present invention, by arranging an appropriate optical lens in the optical path, the focal length f ₃ of the superimposing optical system including the superimposing lens and the optical lens is adjusted to adjust the size of the illumination area. Therefore, it is not necessary to adjust the size of the first small lens and the focal length f ₁ of the second small lens in order to adjust the size of the illumination area. Therefore, even if the size of the electro-optic modulator is changed, the illumination optical system before the change of the electro-optic modulator can be used as it is.

  Thus, according to the projector of the present invention, even if the electro-optic modulation device is changed, the illumination optical system before the change of the electro-optic modulation device can be used as it is, so that the illumination optical system is redesigned. As a result of eliminating the necessity and reducing the number of steps, it is possible to suppress an increase in the manufacturing cost of the projector.

  As described above, the projector of the present invention uses the projector in which the size of the illumination area can be easily adjusted, or the illumination optical system before the change of the electro-optic modulation device even if the size of the electro-optic modulation device is changed. It becomes the projector which can do.

  In the projector according to the aspect of the invention, the first dichroic mirror that separates the light from the superimposing lens into the first color light, the second color light, and the third color light, the second color light from the first dichroic mirror, and A color separation light guide optical system having a second dichroic mirror that separates the third color light into the second color light and the third color light, and the electro-optic modulator as the first to third color lights, respectively. Modulating first to third electro-optic modulators, a color synthesizing optical system that synthesizes the color lights modulated by the first to third electro-optic modulators, and emits them to the projection optical system, and the optical lens As described above, the first optical lens disposed between the first dichroic mirror and the first electro-optic modulation device, and the first dichroic mirror and the second dichroic mirror are disposed. A first optical lens having a focal length different from a focal length of the superimposing lens and having a focal position substantially the same as the focal position of the superimposing lens. A superimposing optical system is configured with the superimposing lens, and the second optical lens has a focal length different from the focal length of the superimposing lens, and has a focal position substantially the same as the focal position of the superimposing lens. It is preferable that the superimposing optical system is configured together with the superimposing lens.

  Therefore, according to the projector of the present invention, the second superimposing optical system including the first superimposing optical system including the superimposing lens and the first optical lens, and the superimposing lens and the second optical lens. Therefore, it is possible to adjust the size of the illumination area relatively freely in each of the first to third electro-optic modulation devices.

  Further, according to the projector of the present invention, it is possible to arrange the first optical lens and the second optical lens in a place having a relatively large space.

  In addition, according to the projector of the present invention, the focal position of the superimposing optical system composed only of the superimposing lens when the optical lens is not disposed in the optical path, and the superimposing lens and the optical lens when the optical lens is disposed in the optical path. Therefore, even if the optical lens is arranged in the optical path, it is not necessary to change the positional relationship between the superimposing lens and each electro-optic modulation device. Therefore, even if the size of the electro-optic modulation device is changed, the color separation light guide optical system before the change of the electro-optic modulation device can be used as it is without changing the color separation light guide optical system. Become.

  Thus, according to the projector of the present invention, even if the electro-optic modulation device is changed, the color separation light guide optical system before the change of the electro-optic modulation device can be used as it is. As a result of eliminating the need to redesign the optical system and reducing the number of steps, it is possible to suppress an increase in the manufacturing cost of the projector.

  In the projector according to the aspect of the invention, it is preferable that at least one of the first optical lens and the second optical lens is a convex meniscus lens.

  By using meniscus lenses as the first optical lens and the second optical lens of the present invention, the position of the principal point of the superimposing optical system is adjusted in the direction along the optical axis while maintaining the focal position of the superimposing optical system. Therefore, it is possible to adjust the focal length of the superimposing optical system while maintaining the focal position of the superimposing optical system. As a result, the size of the illumination area in the image forming area can be adjusted.

  In the projector according to the aspect of the invention, it is preferable that at least one of the first optical lens and the second optical lens is a compound lens including two or more lenses.

  By using a composite lens composed of two or more lenses as the first optical lens and the second optical lens of the present invention, the position of the principal point of the superimposing optical system can be changed while maintaining the focal position of the superimposing optical system. Since it is possible to adjust in the direction along the axis, the focal length of the superimposing optical system can be adjusted while maintaining the focal position of the superimposing optical system. As a result, the size of the illumination area in the image forming area can be adjusted.

  In the projector according to the aspect of the invention, it is preferable that the first optical lens and the second optical lens have the same shape.

  With this configuration, it is possible to use lenses having the same shape as the first optical lens and the second optical lens, so that the manufacturing cost of the projector can be reduced.

  In the projector according to the aspect of the invention, the power of the lens arranged in the optical path through which the relatively long wavelength color light passes among the first optical lens and the second optical lens is relatively short wavelength color light. It is preferable that the power of the lens disposed in the optical path through which the lens passes is larger.

In general, the refractive index of a lens has wavelength dispersion characteristics, and the refractive index of light having a relatively long wavelength is smaller than the refractive index of light having a relatively short wavelength. For this reason, since light having a relatively long wavelength is less refracted than light having a relatively short wavelength, if the powers of the first optical lens and the second optical lens are set to be the same, a relatively long wavelength is used. The size of the illumination area irradiated on the image forming area is likely to be different between the case where the light of the incident light and the light of a relatively short wavelength are incident.
However, in such a case, by configuring as described above, light having a relatively long wavelength passes through a lens having a higher power than light having a relatively short wavelength. Difficult to compensate for, the size of the illumination area irradiated to the image forming area is the same when relatively long wavelength light is incident and when relatively short wavelength light is incident Will be able to.
For this reason, an illumination area of the same size is formed for each electro-optic modulation device corresponding to each color light, the illumination state for each color light becomes uniform, color unevenness is reduced, and color reproducibility is improved. .

  The present invention is particularly effective when applied to a projector using a lens array unit in which the first lens array and the second lens array are integrally formed as the first lens array and the second lens array.

  The lens array unit in which the first lens array and the second lens array are integrally molded is usually manufactured by press molding glass. In this case, if the distance between the first lens array and the second lens array is long, the thickness of the lens array unit is increased, and there is a possibility that cracks and chips may occur during manufacturing. Further, when the thickness of the lens array unit is increased, the weight of the lens array unit is increased and the material cost is increased.

On the other hand, according to the projector of the present invention, since the focal length of the superimposing optical system can be adjusted as described above, the focal length of the superposing optical system can be shortened. When you reduce the focal length f ₃ of the superposition optical system in the projector of the present invention, in the case of using an electro-optic modulator of the prior art the same size, from the superimposing lens and the optical path length to each electro-optic modulator illumination The focal length f ₁ of the second small lens (and the first small lens) can be shortened while maintaining the size of the region. Of course, the focal length f ₁ of the second small lens (and the first small lens) can be shortened even when an electro-optic modulation device smaller than the conventional one is used. Therefore, the distance between the first lens array and the second lens array can be shortened, and a thin lens array unit in which the first lens array and the second lens array are integrally formed is easily manufactured. It becomes possible. In addition, since a thin lens array unit can be used for a projector, the projector can be reduced in size, the lens array unit can be reduced in weight, and material costs can be reduced. Furthermore, when arranging various optical components, it is not necessary to align the first lens array and the second lens array, and after arranging the various optical components, the first lens array and the second lens are arranged. It becomes possible to suppress degradation of the position accuracy of the array.

  In the present invention, as the first lens array and the second lens array, light from the first lens array is guided to the second lens array between the first lens array and the second lens array. The present invention is also effective when applied to a projector using a lens array unit in which the first lens array and the second lens array are joined via the translucent member.

  In order to reduce the size of the projector, there is a demand for the lens array unit as described above to reduce the thickness of the light-transmitting member in order to reduce the weight of the lens array unit and reduce the material cost.

In this case, according to the projector of the present invention, since the focal length of the superimposing optical system can be adjusted as described above, the focal length of the superposing optical system can also be shortened. When you reduce the focal length f ₃ of the superposition optical system in the projector of the present invention, in the case of using an electro-optic modulator of the prior art the same size, from the superimposing lens and the optical path length to each electro-optic modulator illumination The focal length f ₁ of the second small lens (and the first small lens) can be shortened while maintaining the size of the region. Of course, the focal length f ₁ of the second small lens (and the first small lens) can be shortened even when an electro-optic modulation device smaller than the conventional one is used. For this reason, it is possible to shorten the distance between the first lens array and the second lens array, and it is possible to easily manufacture a lens array unit having a thin light-transmitting member. In addition, since a thin lens array unit can be used for a projector, the projector can be reduced in size, the lens array unit can be reduced in weight, and material costs can be reduced. Furthermore, when arranging the various optical components, the first lens array and the second lens array are previously aligned with each other and then joined to the translucent member. Since it is only necessary to adjust the position of the lens array unit having other optical components and other optical components, it is possible to easily perform the alignment operation of various optical components including the lens array unit, and various optical components. After the arrangement, it is possible to prevent the positional accuracy of the first lens array and the second lens array from deteriorating.

In the projector of the present invention described above, it is preferable that the light transmitting member has a refractive index substantially equal to that of the first lens array and the second lens array.
Further, the adhesive for bonding the first lens array and the light transmitting member and the light transmitting member and the second lens array, respectively, has a refractive index substantially equal to that of the first lens array and the second lens array. It is preferable to have.

  By configuring in this way, it becomes possible to further suppress the reflection of light at the interface between each of the first lens array and the second lens array and the translucent member. The loss of light quantity can be further reduced.

  In the projector according to the aspect of the invention, it is preferable that the translucent member has a linear expansion coefficient substantially equal to that of the first lens array and the second lens array.

  By configuring in this way, it becomes possible to suppress the generation of thermal stress accompanying the temperature change due to the use of the projector, and therefore damage at the junction between the first lens array and the second lens array and the translucent member is prevented. It becomes possible to suppress.

  Accordingly, in the projector of the present invention described above, it is preferable that the translucent member is made of the same base material as the first lens array and the second lens array.

  In the projector according to the aspect of the invention, the light source device includes an ellipsoidal reflector, an arc tube having a light emission center near a first focal point of the ellipsoidal reflector, and the focused light reflected by the ellipsoidal reflector. It is preferable to have a concave lens that emits toward the array.

  With this configuration, the light source device emits an illumination light beam that is smaller than the size of the ellipsoidal reflector, so that the projector can be miniaturized.

  In the projector according to the aspect of the invention, it is preferable that the arc tube is provided with a reflection unit that reflects light emitted from the arc tube toward the illuminated region toward the ellipsoidal reflector.

  With this configuration, light emitted from the arc tube toward the illuminated area is reflected toward the ellipsoidal reflector, so that the size of the arc tube covers the illuminated area side end. Therefore, it is not necessary to set the size of the ellipsoidal reflector, and the ellipsoidal reflector can be miniaturized. As a result, the projector can be miniaturized.

  In the projector according to the aspect of the invention, between the second lens array and the superimposing lens, approximately one type of linearly polarized light in which the polarization directions of the partial light beams divided by the first lens array are aligned in the polarization direction. It is preferable to arrange a polarization conversion element that emits light.

  With this configuration, the projector of the present invention is particularly suitable for an electro-optic modulation device of a type that modulates polarized light, for example, a projector including an electro-optic modulation device using a liquid crystal panel.

  The projector manufacturing method of the present invention includes a light source device that emits an illumination light beam, a first lens array that includes a plurality of first small lenses that divide the illumination light beam from the light source device into a plurality of partial light beams, A second lens array having a plurality of second small lenses corresponding to the first small lenses, a superimposing lens for superimposing the partial light beams from the second lens array on the illuminated area, and superimposing by the superimposing lens A projector manufacturing method comprising: an electro-optic modulation device that modulates light according to image information; and a projection optical system that projects light modulated by the electro-optic modulation device, the focal length of the superimposing lens As an optical lens that forms a superimposing optical system having a different focal length and substantially the same focal position as the superimposing lens together with the superimposing lens, Steps of preparing a plurality of types of optical lenses having different distances, and selecting and arranging any of the plurality of types of optical lenses having different focal lengths, or any of the plurality of types of optical lenses having different focal lengths The step of adjusting the focal length of the superimposing optical system so that the size of the illumination area of the light emitted from the superimposing optical system matches the size of the image forming area of the electro-optic modulator by not arranging It is characterized by including.

  For this reason, according to the projector manufacturing method of the present invention, any one of a plurality of types of optical lenses prepared in advance is selected and arranged, or any of a plurality of types of optical lenses having different focal lengths. Since the size of the illumination area can be adjusted by an extremely simple task of not arranging the light source, the position of each optical element in the illumination optical system is adjusted to adjust the size of the illumination area as in the past. Therefore, it is possible to greatly reduce labor and work time when adjusting the size of the illumination area.

  For this reason, the projector manufacturing method of the present invention is a projector in which it is easy to adjust the size of the illumination area, or the illumination optical system before the electro-optic modulation device is changed even if the size of the electro-optic modulation device is changed. This is an excellent manufacturing method capable of manufacturing a projector that can be used as it is.

  In the projector manufacturing method of the present invention, before the step of adjusting the focal length of the superimposing optical system, as the superimposing lens, a step of preparing a plurality of types of superimposing lenses having substantially the same focal position and different focal lengths; The size of the illumination area of the light emitted from the superimposing lens can be selected from the plurality of superimposing lenses having different focal lengths as the superimposing lens. A step of roughly adjusting a focal length of the superimposing optical system so as to be adapted to a size of an image forming region, and the step of adjusting the focal length of the superposing optical system is emitted from the superimposing optical system. It is preferable that the focal length of the superimposing optical system is finely adjusted so that the size of the illumination area of light matches the size of the image forming area of the electro-optic modulator.

  By adopting such a method, even if the size of the electro-optic modulation device is significantly changed, the size of the illumination area generated by the superimposing optical system is greatly increased by exchanging the superimposing lens together with the optical lens. Since the size of the illumination area can be finely adjusted by the optical lens, the illumination optical system before the change of the electro-optic modulation device can be used as it is.

  In the projector manufacturing method of the present invention, the projector includes a first dichroic mirror that separates light from the superimposing lens into first color light, second color light, and third color light, and the first dichroic mirror. A color separation light guide optical system having a second dichroic mirror for separating the second color light and the third color light into the second color light and the third color light, and the first to first as the electro-optic modulator. First to third electro-optic modulation devices that respectively modulate three color lights, and a color synthesis optical system that synthesizes the color lights modulated by the first to third electro-optic modulation devices and emits them to the projection optical system A step of preparing a plurality of types of optical lenses having different focal lengths, and having a focal length different from the focal length of the superimposing lens. Preparing a plurality of types of first optical lenses having different focal lengths as a first optical lens that constitutes a first superimposing optical system having substantially the same focal position as the superposition lens together with the superimposing lens; As a second optical lens that forms a second superimposing optical system having a focal length different from the focal length of the superimposing lens and having a focal position substantially the same as the focal position of the superimposing lens together with the superimposing lens. Preparing a plurality of types of second optical lenses having different focal lengths, and adjusting the focal length of the superimposing optical system from among the plurality of types of first optical lenses having different focal lengths. Light that is emitted from the first superimposing optical system by selecting any one of them or arranging none of the plurality of types of first optical lenses having different focal lengths Adjusting the focal length of the first superimposing optical system so that the size of the illumination region matches the size of the image forming region of the first electro-optic modulator, and a plurality of types with different focal lengths By selecting any one of the second optical lenses and disposing any of the plurality of types of second optical lenses having different focal lengths, the light is emitted from the second superimposing optical system. The focus of the second superposition optical system so that the size of the illumination area of the light to be matched with the size of the image forming area of the second electro-optic modulation device and / or the third electro-optic modulation device And a step of adjusting the distance.

  A color separation light guide optical system that separates light from the superimposing lens into first to third color lights, and first to third electro-optic modulation devices that modulate the first to third color lights, respectively; Even in a projector having a plurality of illumination regions superimposed by the optical system, the light that illuminates the first electro-optic modulation device is configured by the superimposing lens and the first optical lens by the above-described method. A first superimposing optical system that emits light, a superimposing lens, and a second optical lens, and a second light that illuminates the second electro-optic modulator and / or the third electro-optic modulator. In each of the superposition optical systems, the size of the illumination area can be adjusted relatively freely.

  Hereinafter, a projector and a method for manufacturing the projector of the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
FIG. 1 is a diagram illustrating an optical system of a projector 1000 according to the first embodiment.
In the following description, three directions orthogonal to each other are defined as a z-axis direction (illumination optical axis 100ax direction in FIG. 1), an x-axis direction (a direction parallel to the paper surface in FIG. 1 and perpendicular to the z-axis), and y. Let it be an axial direction (a direction perpendicular to the paper surface in FIG. 1 and perpendicular to the z-axis).

  As shown in FIG. 1, the projector 1000 according to the first embodiment includes a light source device 110 that emits an illumination light beam, and a plurality of first small lenses 121 that divide the illumination light beam from the light source device 110 into a plurality of partial light beams. The first lens array 120, the second lens array 130 having a plurality of second small lenses 131 corresponding to the plurality of first small lenses 121, and the polarization direction of each partial light beam divided by the first lens array 120, A polarization conversion element 140 that emits as substantially one type of linearly polarized light with a uniform polarization direction, a superimposing lens 160 that superimposes each partial light beam from the polarization conversion element 140 on the illuminated area, the first optical lens 170, and the first optical lens 170 The superimposing optical system 150 including the two optical lenses 180 and the color-separated light guide light that separates the light from the superimposing lens 160 into three color lights and guides them to the illuminated area. System 200, three electro-optic modulators 400R, 400G, 400B for modulating each of the three color lights separated by the color separation light guide optical system 200 according to image information, and electro-optic modulators 400R, 400G, 400B A cross dichroic prism 500 as a color synthesizing optical system for synthesizing the color light modulated by the light, a projection optical system 600 for projecting the light synthesized by the cross dichroic prism 500 onto a projection surface such as a screen SCR, and an optical element housing case. A projector including a body 10.

  The light source device 110 includes an ellipsoidal reflector 114, an arc tube 112 having a light emission center near the first focal point of the ellipsoidal reflector 114, and light emitted from the arc tube 112 toward the illuminated area. An auxiliary mirror 116 as a reflecting means for reflecting the light toward the ellipsoidal reflector 114, and a concave lens 118 that converts the focused light reflected by the ellipsoidal reflector 114 into parallel light and emits it toward the first lens array 120. Have. The light source device 110 emits a light beam having the illumination optical axis 100ax as a central axis.

The arc tube 112 has a tube bulb portion and a pair of sealing portions extending on both sides of the tube bulb portion.
The ellipsoidal reflector 114 includes a cylindrical neck that is inserted and fixed to one sealing portion of the arc tube 112, and a reflective concave surface that reflects light emitted from the arc tube 112 toward the second focal position. have.

  The auxiliary mirror 116 is provided to face the ellipsoidal reflector 114 with the arc tube 112 interposed therebetween, and returns light that has not been directed to the ellipsoidal reflector 114 out of the light emitted from the arctube 112 to the arctube 112. To enter.

  The concave lens 118 is disposed on the illuminated area side of the ellipsoidal reflector 114. Then, the light from the ellipsoidal reflector 114 is emitted toward the first lens array 120.

  The first lens array 120 has a function as a light beam splitting optical element that splits light from the concave lens 118 into a plurality of partial light beams, and a plurality of first lens arrays 120 arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax. It has a configuration provided with one small lens 121. The outer shape of the first small lens 121 is similar to the outer shape of the image forming region of the electro-optic modulation devices 400R, 400G, and 400B.

  The second lens array 130 is an optical element that collects a plurality of partial light beams divided by the first lens array 120, and in the same manner as the first lens array 120, in a matrix form in a plane orthogonal to the illumination optical axis 100ax. It has the structure provided with the some 2nd small lens 131 arranged.

The polarization conversion element 140 is a polarization conversion element that emits the polarization direction of each partial light beam divided by the first lens array 120 as approximately one type of linearly polarized light having a uniform polarization direction.
The polarization conversion element 140 transmits one linear polarization component of the polarization component included in the illumination light beam from the light source device 110 as it is, and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 100ax. And the other linearly polarized light component reflected by the polarization separation layer in a direction parallel to the illumination optical axis 100ax, and the other linearly polarized light component reflected by the reflective layer is converted into one linearly polarized light component. And a retardation plate.

The superimposing optical system 150 includes a superimposing lens 160 that superimposes each partial light beam from the polarization conversion element 140 on the illuminated area, a first optical lens 170, and a second optical lens 180.
Although not shown here, in the superimposing optical system 150, the first color light in the plurality of partial light beams separated by the first lens array 120 is superimposed on the image forming area of the first electro-optic modulation device 400R. The superimposing optical system configured by the superimposing lens 160 and the first optical lens 170 is referred to as a first superimposing optical system, and the second color light and the second color light among the plurality of partial light beams separated by the first lens array 120. A superimposing optical system composed of a superimposing lens 160 and a second optical lens 180 for superimposing the third color light on the image forming regions of the second electro-optic modulation device 400G and the third electro-optic modulation device; This is called a superimposing optical system.

  The first optical lens 170 and the second optical lens 180 will be described in detail later.

  The color separation light guide optical system 200 includes a first dichroic mirror 210 and a second dichroic mirror 220, reflection mirrors 230, 240, 250, an incident side lens 260, and a relay lens 270. The color separation light guide optical system 200 converts the illumination light beam emitted from the superimposing lens 160 into three color lights: red light as first color light, green light as second color light, and blue light as third color light. And has a function of guiding the respective color lights to the first to third electro-optic modulation devices 400R, 400G, and 400B to be illuminated.

  The first dichroic mirror 210 and the second dichroic mirror 220 are optical elements on which a wavelength selection film that reflects a light beam in a predetermined wavelength region and transmits a light beam in another wavelength region is formed on a substrate. The first dichroic mirror 210 is a mirror that transmits a red light component and reflects other color light components. The second dichroic mirror 220 is a mirror that transmits a blue light component and reflects a green light component.

The red light component reflected by the first dichroic mirror 210 passes through the first optical lens 170, is bent by the reflection mirror 230, and passes through the condenser lens 300R, and the first electro-optic modulation device 400R for red light. Incident on the image forming area.
The condensing lens 300R is provided to convert each partial light beam from the first optical lens 170 into a light beam substantially parallel to each principal ray. The condensing lenses 300G and 300B disposed in the preceding stage of the optical path of the other second electro-optic modulation device 400G and third electro-optic modulation device 400B are also configured similarly to the condensing lens 300R.

  The green light component and the blue light component that have passed through the first dichroic mirror 210 will pass through the second optical lens 180. The green light component that has passed through the second optical lens 180 is reflected by the second dichroic mirror 220, passes through the condenser lens 300G, and passes through the image forming area of the second electro-optic modulation device 400G for green light. Illuminate. On the other hand, the blue light component that has passed through the second optical lens 180 is transmitted through the second dichroic mirror 220, and enters the incident side lens 260, the incident side reflection mirror 240, the relay lens 270, the emission side reflection mirror 250, and the condensing light. The image forming area of the third electro-optic modulation device 400B for blue light is illuminated through the lens 300B. The incident side lens 260, the relay lens 270, and the reflection mirrors 240 and 250 have a function of guiding the blue light component transmitted through the second dichroic mirror 220 to the third electro-optic modulation device 400B.

  The reason that the incident side lens 260, the relay lens 270, and the reflection mirrors 240 and 250 are provided in the optical path of blue light is that the length of the optical path of blue light is longer than the length of the optical paths of other color lights. For this reason, a decrease in light use efficiency due to light divergence or the like is prevented. The projector 1000 according to Embodiment 1 has such a configuration because the length of the optical path of blue light is long. However, the length of the optical path of red light is increased, and the incident side lens 260 and the relay lens 270 are configured. And the structure which uses the reflective mirrors 240 and 250 for the optical path of red light is also considered.

The first to third electro-optic modulators 400R, 400G, and 400B form a color image by modulating an illumination light beam according to image information, and are illumination targets of the light source device 110. Although not shown, incident side polarizing plates are interposed between the condenser lenses 300R, 300G, and 300B and the electro-optic modulators 400R, 400G, and 400B, respectively. Between the 400G and 400B and the cross dichroic prism 500, an exit side polarizing plate is interposed. The incident-side polarizing plate, the electro-optic modulators 400R, 400G, and 400B and the exit-side polarizing plate modulate the incident color light.
The first to third electro-optic modulators 400R, 400G, and 400B are obtained by sealing and enclosing a liquid crystal that is an electro-optic material in a pair of transparent glass substrates. For example, using a polysilicon TFT as a switching element, the polarization direction of one type of linearly polarized light emitted from the incident side polarizing plate is modulated in accordance with given image information.

  The cross dichroic prism 500 as a color synthesis optical system is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the emission side polarizing plate. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on a substantially X-shaped interface in which the right-angle prisms are bonded together. The dielectric multilayer film formed at one interface having a substantially X shape reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. Red light and blue light are bent by the dielectric multilayer film and aligned with the traveling direction of green light, so that three color lights are synthesized.

  The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form a large screen image on the screen SCR.

  The projector 1000 according to the first embodiment includes a first optical lens 170 and a second optical lens 180 as optical lenses, and a first optical lens fixing device 172 and a second optical lens fixing device 182 as optical lens fixing devices. It is characterized by having. This will be described in detail below.

FIG. 2 is a diagram for explaining the effect of the projector 1000 according to the first embodiment. FIG. 2A shows the focal length f ₁ of the second lens array 130 and the _first focal length f ₁ when the first optical lens 170 is not arranged in the optical path and the first superimposing optical system is composed of only the superimposing lens 160. 1 of the relationship between the focal length f ₂ of the superposition optical system is a diagram schematically illustrating. FIG. 2B shows the second lens array 130 in the case where the first optical lens 170 is arranged in the optical path and the first superimposing optical system is composed of the superimposing lens 160 and the first optical lens 170. it is a diagram schematically showing the relationship between the focal length f ₁ and the focal length f ₃ of the first superimposing system. FIG. 2C is a schematic diagram showing an illumination state in the image forming region S of the first electro-optic modulation device 400R at the time of FIG. FIG. 2D is a schematic diagram showing an illumination state in the image forming region S of the first electro-optic modulation device 400R at the time of FIG. However, in FIGS. 2 (a) and 2 (b), for the sake of brevity, the light path of red light among red light, green light and blue light is illustrated and arranged in the optical path of red light. The condensing lens 300R and the electro-optic modulation device 400R are shown, and the polarization conversion element 140, the first dichroic mirror 210, and the reflection mirror 230 are not shown.

  In the projector 1000 according to the first embodiment, the focal length is the length from the principal point of the optical system to the focal point, and the focal position is the focal position of the optical system.

  As shown in FIG. 1, the projector 1000 according to the first embodiment includes a first optical lens fixing device 172 for detachably fixing the first optical lens 170 to the optical element housing case 10, The projector includes a second optical lens fixing device 182 for detachably fixing the second optical lens 180 to the optical element housing case 10.

The first optical lens 170 is a convex meniscus lens having the largest thickness on the optical axis in the first optical lens 170 alone. The first optical lens 170 is disposed between the first dichroic mirror 210 and the reflection mirror 230 with the convex surface facing the light incident side, and is further fixed by the first optical lens fixing device 172. When the first optical lens 170 is disposed between the first dichroic mirror 210 and the reflection mirror 230 as shown in FIGS. 1 and 2B, the focal point of the superimposing lens 160 together with the superimposing lens 160 is obtained. This constitutes a first superimposing optical system having a focal length f ₃ longer than the distance f ₂ and substantially the same focal position as that of the superimposing lens 160.

When the first optical lens 170 is not disposed between the first dichroic mirror 210 and the reflection mirror 230, as shown in FIG. 2A, the first superimposing optical system is the superimposing lens 160 in the optical path of red light. Therefore, the focal length of the first superimposing optical system is f ₂ that is the focal length of the superimposing lens 160. On the other hand, when the first optical lens 170 is disposed between the first dichroic mirror 210 and the reflection mirror 230, as shown in FIG. 2B, the first superimposing optical system in the optical path of red light. Is composed of the superimposing lens 160 and the first optical lens 170, the focal length of the first superimposing optical system is f ₃ , and the first superimposing optical in the case of being composed of only the superimposing lens 160. It becomes longer than the focal length f _{2 of the} system. At this time, the focal position of the first superimposing optical system composed of only the superimposing lens 160 when the first optical lens 170 is not disposed, and the superimposing lens 160 and the first when the first optical lens 170 is disposed. The focal position of the first superimposing optical system composed of the optical lens 170 is substantially the same.

  The first optical lens fixing device 172 is for detachably fixing the first optical lens 170 to the optical element housing 10. In addition, as a fixing means for fixing the first optical lens 170, for example, a well-known fixing means can be used in addition to a fixing means having a groove for slidably holding an end portion of the optical lens 170. .

The second optical lens 180 is a convex meniscus lens having the largest thickness on the optical axis in the second optical lens 180 alone. The second optical lens 180 is disposed between the first dichroic mirror 210 and the second dichroic mirror 220 with the convex surface facing the light incident side, and is further fixed by the second optical lens fixing device 182. . When the second optical lens 180 is disposed between the first dichroic mirror 210 and the second dichroic mirror 220, the second optical lens 180 has a focal length f ₃ longer than the focal length f _{2 of} the superimposing lens 160 together with the superimposing lens 160. The second superposition optical system having a focus position substantially the same as the focus position of the superposition lens 160 is configured.

As in the case of the first optical lens 170, when the second optical lens 180 is not disposed between the first dichroic mirror 210 and the second dichroic mirror 220, the second optical lens 180 is the first in the optical path of green light and the optical path of blue light. Since the second superimposing optical system is composed of only the superimposing lens 160, the focal length of the second superimposing optical system is f ₂ which is the focal length of the superimposing lens 160. On the other hand, when the second optical lens 180 is disposed between the first dichroic mirror 210 and the second dichroic mirror 220, the second superposition optical system is a superposition lens in the optical path of green light and the optical path of blue light. 160 and the second optical lens 180, the focal length of the second superimposing optical system is f ₃ , and the focal point of the second superimposing optical system when only the superimposing lens 160 is configured. It is longer than the distance f _2. At this time, the focal position of the second superimposing optical system composed of only the superimposing lens 160 when the second optical lens 180 is not disposed, and the superimposing lens 160 and the second when the first optical lens 180 is disposed. The focal position of the second superimposing optical system composed of the optical lens 180 is substantially the same.

  The second optical lens fixing device 182 is for fixing the second optical lens 180 to the optical element housing case 10. In addition, as a fixing means for fixing the second optical lens 180, for example, a fixing means having a groove for slidably holding an end portion of the second optical lens 180, or a known fixing means is used. be able to.

For this reason, when it is necessary to adjust the size of the illumination area L in the electro-optic modulation devices 400R, 400G, and 400B, the projector 1000 according to the first embodiment uses the first optical lens 170 as the first dichroic. The second optical lens 180 can be disposed between the first dichroic mirror 210 and the second dichroic mirror 220 while being disposed between the mirror 210 and the reflection mirror 230 (first electro-optic modulation device 400R). Therefore, the focal length f ₃ of the superimposing optical system 150 including the superimposing lens 160, the first optical lens 170, and the second optical lens 180 can be adjusted.

At this time, the size of the illumination area L is set to the size of the outer shape of the first small lens 121 of the first lens array 120 and the superposition optical system for the focal length f ₁ of the second small lens 131 of the second lens array 130. It is multiplied by the ratio of the focal length f ₃ of 150 (= f ₃ / f ₁ (magnification)). That is, in the optical path of red light, the focal length f ₃ of the first superimposing optical system composed of the superimposing lens 160 and the first optical lens 170 is the first superimposing optical system composed of only the superimposing lens 160. since longer than the focal length f ₂ of, by arranging the first optical lens 170 to a predetermined position in the optical path, it becomes possible to increase the size of the illumination area L. Similarly, in the optical path of green light and the optical path of blue light, the size of the illumination region L can be increased by arranging the second optical lens 180 in the optical path.

  Therefore, according to the projector 1000 according to the first embodiment, the first optical lens 170 or the second optical lens 180 is disposed at a predetermined position in the optical path, and the first optical lens fixing device 172 or the second optical lens. By fixing with the fixing device 182, the size of the illumination region L can be adjusted to an appropriate size with respect to the image forming region S, as shown in FIGS. 2 (c) and 2 (d).

  Further, according to the projector 1000 according to the first embodiment, the superimposing optical system 150 including only the superimposing lens 160 when the first optical lens 170 and the second optical lens 180 are not disposed at predetermined positions in the optical path. A superposition optical system comprising a focus position, a superposition lens 160 when the first optical lens 170 and the second optical lens 180 are arranged at predetermined positions in the optical path, and the first optical lens 170 and the second optical lens 180. Since the focal positions of 150 can be made substantially the same, even if the first optical lens 170 and the second optical lens 180 are arranged at predetermined positions in the optical path, the electro-optic modulation devices 400R, 400G, and 400B. The image forming region S is irradiated with illumination light having a relatively uniform in-plane light intensity distribution without defocusing.

  Further, according to the projector 1000 according to the first embodiment, the first optical lens fixing device 172 and the second optical lens are arranged by arranging the first optical lens 170 and the second optical lens 180 at predetermined positions in the optical path. The size of the illumination area L can be adjusted by a very simple configuration of fixing by the fixing device 182.

On the other hand, according to the projector 1000 according to the first embodiment, even when the size of the electro-optic modulation device is changed, the first optical lens 170 and the second optical lens 180 are placed in the optical path for the same reason as described above. Therefore, the focal length f ₃ of the superimposing optical system 150 can be adjusted. As a result, the size of the illumination region L is adjusted, and the changed image of the electro-optic modulation device is adjusted. It can be adapted to the size of the forming area.

Further, according to the projector 1000 according to the first embodiment, the focal length f ₃ of the superimposing optical system 150 is adjusted by arranging the first optical lens 170 and the second optical lens 180 at predetermined positions in the optical path. Since the size of the illumination area L can be adjusted, the size of the first small lens 121 and the focal length f ₁ of the second small lens 131 are adjusted to adjust the size of the illumination area L. There is no need. Therefore, even if the size of the electro-optic modulator is changed, the illumination optical system before the change of the electro-optic modulator can be used as it is.

  As described above, according to the projector 1000 according to the first embodiment, even if the electro-optic modulation device is changed, the illumination optical system before the change of the electro-optic modulation device can be used as it is. As a result of eliminating the need for redesign and reducing the number of steps, it is possible to suppress an increase in the manufacturing cost of the projector.

  Therefore, the projector 1000 according to the first embodiment is a projector that can easily adjust the size of the illumination area, or the illumination optical system before the electro-optic modulation device is changed even if the size of the electro-optic modulation device is changed. Can be used as it is.

  As described above, the projector 1000 according to the first embodiment includes the first optical lens 170 and the second optical lens 180 as the optical lenses. The first optical lens 170 forms a first superimposing optical system having a focal length different from the focal length of the superimposing lens 160 and having a focal position substantially the same as the focal position of the superimposing lens 160 together with the superimposing lens 160. In addition, the second optical lens 180 includes a second superposition optical system having a focal length different from the focal length of the superimposing lens 160 and substantially the same focal position as that of the superimposing lens 160 together with the superimposing lens 160. To do.

  Therefore, according to the projector 1000 according to the first embodiment, the projector 1000 includes the first superimposing optical system including the superimposing lens 160 and the first optical lens 170, and the superimposing lens 160 and the second optical lens 180. Therefore, the size of the illumination area can be adjusted relatively freely in each of the first to third electro-optic modulators 400R, 400G, and 400B. It becomes.

  Further, according to the projector 1000 according to the first embodiment, it is possible to arrange the first optical lens 170 and the second optical lens 180 in a place where there is a relatively large space.

  Further, according to the projector 1000 according to the first embodiment, the superimposing optical system 150 including only the superimposing lens 160 when the first optical lens 170 and the second optical lens 180 are not disposed at predetermined positions in the optical path. A superposition optical system comprising a focus position, a superposition lens 160 when the first optical lens 170 and the second optical lens 180 are arranged at predetermined positions in the optical path, and the first optical lens 170 and the second optical lens 180. Since the focal positions of 150 can be made substantially the same, even if the first optical lens 170 and the second optical lens 180 are arranged at predetermined positions in the optical path, the superimposing lens 160 and each electro-optic modulation device 400R. , 400G, 400B without changing the positional relationship. For this reason, even if the size of the electro-optic modulation device is changed, the color separation light guide optical system 200 before the change of the electro-optic modulation device can be used as it is without changing the color separation light guide optical system. become.

  As described above, according to the projector 1000 according to the first embodiment, even if the electro-optic modulation device is changed, the color separation light guide optical system 200 before the change of the electro-optic modulation device can be used as it is. It is not necessary to redesign the color separation light guide optical system, and the number of man-hours can be reduced. As a result, an increase in the manufacturing cost of the projector can be suppressed.

  Since the projector according to the first embodiment includes the first optical lens fixing device 172 and the second optical lens fixing device 182 described above as the optical lens fixing device, at least the first electro-optical device. It is possible to separately adjust the size of the illumination region in the modulation device 400R and the size of the illumination region in the second and third electro-optic modulation devices 400G and 400B.

  In the projector 1000 according to the first embodiment, the first optical lens 170 and the second optical lens 180 are convex meniscus lenses.

  By using convex meniscus lenses as the first optical lens 170 and the second optical lens 180, the position of the principal point of the superimposing optical system 150 in the direction along the optical axis is maintained while maintaining the focal position of the superimposing optical system 150. Since adjustment is possible, the focal length of the superimposing optical system 150 can be adjusted while maintaining the focal position of the superimposing optical system 150. As a result, the size of the illumination area L in the image forming area can be adjusted.

In the projector 1000 according to the first embodiment, the first optical lens 170 and the second optical lens 180 are arranged with the convex surface facing the light incident side. The focal length f ₃ of the superimposing optical system 150 can be increased while maintaining the above. As a result, the size of the illumination area L in the image forming area S can be increased.

  In the projector 1000 according to the first embodiment, the first optical lens 170 and the second optical lens 180 have the same shape.

  As a result, lenses having the same shape can be used as the first optical lens 170 and the second optical lens 180, and thus the manufacturing cost of the projector can be reduced.

  The first optical lens 170, the second optical lens 180, the first optical lens fixing device 172, and the second optical lens fixing device 182 in the projector 1000 according to the first embodiment have been described in detail above. The projector 1000 according to 1 also has the following characteristics.

  In the projector 1000 according to the first embodiment, as illustrated in FIG. 1, the light source device 110 includes an ellipsoidal reflector 114, an arc tube 112 having a light emission center near the first focal point of the ellipsoidal reflector 114, and an ellipsoidal reflector. And a concave lens 118 that emits the focused light reflected by 114 toward the first lens array 120.

  Thereby, since the illumination light beam smaller than the size of the ellipsoidal reflector 114 is emitted from the light source device 110, the projector can be miniaturized.

  In the projector 1000 according to the first embodiment, the arc tube 112 is provided with an auxiliary mirror 116 as a reflection unit that reflects the light emitted from the arc tube 112 toward the illuminated area toward the ellipsoidal reflector 114. Yes.

  As a result, the light emitted from the arc tube 112 toward the illuminated area is reflected toward the ellipsoidal reflector 114, and thus the elliptical shape is formed so as to cover the illuminated area side end of the arc tube 112. It is not necessary to set the size of the surface reflector 114, and the ellipsoidal reflector can be downsized. As a result, the projector can be downsized.

  Next, a method for manufacturing the projector according to the first embodiment will be described.

  The projector manufacturing method according to the first embodiment is a method for manufacturing the projector 1000 described above, and a step of preparing a plurality of types of first optical lenses having different focal lengths as the first optical lens 170; As the second optical lens 180, a step of preparing a plurality of types of second optical lenses having different focal lengths and a method of selecting and arranging one of a plurality of types of first optical lenses having different focal lengths, or By disposing any of the plurality of types of first optical lenses having different focal lengths, the size of the illumination area of the light emitted from the first superimposing optical system is changed to the image forming area of the first electro-optic modulation device 400R. Adjusting the focal length of the first superimposing optical system to match the size of the first optical system, and selecting one of a plurality of types of second optical lenses having different focal lengths. The size of the illumination area of the light emitted from the second superimposing optical system is changed to the second electro-optic modulator 400G by arranging or not arranging any of the plurality of types of second optical lenses having different focal lengths. And / or adjusting the focal length of the second superimposing optical system so as to match the size of the image forming area of the third electro-optic modulation device 400B.

  Specifically, first, as the first optical lens 170 and the second optical lens 180 described above, a plurality of types of first optical lenses and second optical lenses having different focal lengths are prepared.

  Next, while confirming the size of the illumination area L in the image forming area S of the electro-optic modulation device 400R, an appropriate one as the first optical lens 170 is selected from the prepared first optical lenses. Deploy. In the case where the size of the illumination area L is suitable for the size of the image forming area S of the electro-optic modulation device 400R without the first optical lens 170 being arranged, the first optical lens is used. It is not necessary to arrange the lens 170.

Similarly to the case of the first optical lens 170, the second optical lens 180 is also prepared while confirming the size of the illumination area L in the image forming area S of the electro-optic modulators 400G and 400B. An appropriate one as the second optical lens 180 is selected from the optical lenses of FIG. In the case where the size of the illumination area L is suitable for the size of the image forming area S of the electro-optic modulators 400G and 400B without the second optical lens 180 being disposed, It is not necessary to dispose the optical lens 180.
In this case, a lens having the same shape as the lens selected as the first optical lens 170 is preferably selected and arranged as the second optical lens 180.

  For this reason, according to the method for manufacturing the projector according to the first embodiment, either one of the plurality of first optical lenses or the second optical lens prepared in advance is selected and arranged. Since the size of the illumination area L can be adjusted by an extremely simple work of not arranging the optical elements, the position of each optical element in the illumination optical system is adjusted as in the conventional art to adjust the size of the illumination area. Thus, it is possible to significantly reduce the labor and work time when adjusting the size of the illumination area.

  Therefore, the projector manufacturing method according to the first embodiment is a projector in which the size of the illumination area can be easily adjusted, or the illumination before the electro-optic modulation device is changed even if the size of the electro-optic modulation device is changed. This is an excellent manufacturing method in which a projector capable of using an optical system as it is can be manufactured.

  In the projector manufacturing method according to the first embodiment, it is possible to relatively freely adjust the size of the illumination area in each of the first superimposing optical system and the second superimposing optical system. There is also.

  In the projector 1000 according to the first embodiment, the superimposing optical system is configured by arranging the first optical lens and the second optical lens, which are convex meniscus lenses having a convex surface on the light incident side, at predetermined positions in the optical path. However, the present invention is not limited to this, and the following modifications are possible, for example.

FIG. 3 is a diagram for explaining the effect of the projector 1000a according to the modification of the first embodiment. FIG. 3A shows the focal length f ₁ of the second lens array 130 and the _first focal length f ₁ when the first optical lens 170 is not arranged in the optical path and the first superimposing optical system is composed of only the superimposing lens 160. 1 of the relationship between the focal length f ₂ of the superposition optical system is a diagram schematically illustrating. FIG. 3B shows the second lens array 130 in the case where the first optical lens 170a is arranged in the optical path and the first superimposing optical system is composed of the superimposing lens 160 and the first optical lens 170a. the focal length f ₁ between a diagram schematically showing the relationship between the focal length f ₄ of the first superimposing system. FIG. 3C is a schematic diagram showing an illumination state in the image forming region S of the first electro-optic modulation device 400R at the time of FIG. FIG. 3D is a schematic diagram illustrating an illumination state in the image forming region S of the first electro-optic modulation device 400R in the case of FIG. However, in FIG. 3 (a) and FIG. 3 (b), for the sake of brevity, the light path of red light among red light, green light, and blue light is illustrated and arranged in the optical path of red light. The condensing lens 300R and the electro-optic modulation device 400R are shown, and the polarization conversion element 140, the first dichroic mirror 210, and the reflection mirror 230 are not shown.

  As shown in FIG. 3B, a projector 1000a (not shown) according to a modification of the first embodiment includes a first optical lens 170a and a second optical lens made of a convex meniscus lens having a concave surface on the light incident side. By disposing the optical lens 180a (only the first optical lens 170a is shown in FIG. 3B) at a predetermined position in the optical path, the focal point of the superimposing optical system remains substantially the same. It is characterized by shortening the distance. The first optical lens 170a is a convex meniscus lens having the largest thickness on the optical axis in the first optical lens 170a alone. The second optical lens 180a is a convex meniscus lens having the largest thickness on the optical axis in the second optical lens 180a alone.

  Therefore, according to the projector 1000a according to the modified example of the first embodiment, as shown in FIGS. 3C and 3D, the image forming area is opposite to the projector 1000 according to the first embodiment. The size of the illumination area L in S can be reduced. However, as in the case of the projector 1000 according to the first embodiment, it is possible to adjust the position of the principal point of the superimposing optical system in the direction along the optical axis while maintaining the focal position of the superimposing optical system. The size of the illumination area L in the image forming area can be adjusted.

[Embodiment 2]
FIG. 4 is a diagram illustrating an optical system of the projector 1002 according to the second embodiment. In FIG. 4, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the projector 1002 according to the second embodiment has basically the same configuration as the projector 1000 according to the first embodiment, but includes the first optical lens and the second optical lens. The orientation and the configuration of the first lens array and the second lens array are different from those of the projector 1000 according to the first embodiment.

In the projector 1002 according to the second embodiment, as shown in FIG. 4, the first optical lens 170 and the second optical lens 180 are arranged with the concave surface facing the light incident side. As a result, the focal length f ₃ of the superimposing optical system 150 can be shortened while maintaining the focal position of the superimposing optical system 150.

  Further, in the projector 1002 according to the second embodiment, as shown in FIG. 4, a lens array unit 122 in which the first lens array 120A and the second lens array 130A are integrally formed is used.

  The lens array unit 122 in which the first lens array 120A and the second lens array 130A are integrally molded is usually manufactured by press molding glass. In this case, if the distance between the first lens array 120A and the second lens array 130A is long, the thickness of the lens array unit 122 becomes thick, so that there is a possibility that cracks or chips may occur during manufacturing. Further, when the thickness of the lens array unit 122 is increased, the weight of the lens array unit 122 is increased and the material cost is increased.

On the other hand, according to the projector 1002 according to the second embodiment, the focal length f ₃ of the superimposing optical system 150 can be shortened as described above. For this reason, when an electro-optic modulation device having the same size as the conventional one is used, while maintaining the length of the optical path and the size of the illumination area from the superimposing lens 160 to each of the electro-optic modulation devices 400R, 400G, and 400B, The focal length f ₁ of the second small lens 131A (and the first small lens 121A) can be shortened. Of course, the focal length f ₁ of the second small lens 131A (and the first small lens 121A) can be shortened even when a smaller electro-optic modulation device is used. Therefore, the distance between the first lens array 120A and the second lens array 130A can be shortened, and the thin lens array unit 122 in which the first lens array 120A and the second lens array 130A are integrally molded. Can be easily manufactured. Further, since the thin lens array unit 122 can be used for the projector 1002, the projector 1002 can be reduced in size, the lens array unit 122 can be reduced in weight, and the material cost can be reduced. It becomes possible. Furthermore, when arranging various optical components, it is not necessary to align the first lens array 120A and the second lens array 130A, and after arranging various optical components, the first lens array 120A and It is possible to suppress the deterioration of the positional accuracy of the second lens array 130A.

[Embodiment 3]
FIG. 5 is a diagram illustrating an optical system of the projector 1004 according to the third embodiment. In FIG. 5, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the projector 1004 according to the third embodiment has basically the same configuration as the projector 1000 according to the first embodiment, but includes the first optical lens and the second optical lens. The orientation and the configuration of the first lens array and the second lens array are different from those of the projector 1000 according to the first embodiment.

In the projector 1004 according to the third embodiment, as shown in FIG. 5, the first optical lens 170 and the second optical lens 180 are disposed with the concave surface facing the light incident side. As a result, the focal length f ₃ of the superimposing optical system 150 can be shortened while maintaining the focal position of the superimposing optical system 150.

  In the projector 1004 according to the third embodiment, as shown in FIG. 5, the light from the first lens array 120B is transmitted to the second lens array 130B between the first lens array 120B and the second lens array 130B. A lens array unit 124 having a translucent member 126 for guiding and having the first lens array 120B and the second lens array 130B joined through the translucent member 126 is used.

  In order to reduce the size of the projector, the lens array unit 124 having the first lens array 120B and the second lens array 130B bonded to each other via the light transmitting member 126 can be reduced in weight. There is a demand for reducing the thickness of the translucent member 126 in order to reduce material costs.

In this case, for the same reason as described in the projector 1002 according to the second embodiment, according to the projector 1004 according to the third embodiment, the focal length f ₃ of the superimposing optical system 150 can be shortened. Shortening the distance between the first lens array 120B and the second lens array 130B while maintaining the length of the optical path from the superimposing lens 160 to each electro-optic modulation device 400R, 400G, 400B and the size of the illumination area. Is possible. Therefore, it is possible to easily manufacture the lens array unit 124 in which the light transmitting member 126 is thinned. Further, since the thin lens array unit 124 can be used for the projector 1004, the projector 1004 can be reduced in size, the lens array unit 124 can be reduced in weight, and the material cost can be reduced. It becomes possible. Furthermore, when arranging various optical components, the first lens array 120B and the second lens array 130B are aligned in advance and then joined to the translucent member 126. Since it is only necessary to adjust the position of the lens array unit 124 having the second lens array 130B and other optical components, it is possible to easily perform the alignment operation of various optical components including the lens array unit 124. In addition, after the various optical components are arranged, it is possible to suppress the deterioration of the positional accuracy of the first lens array 120B and the second lens array 130B.

  In the projector 1004 according to the third embodiment, the translucent member 126 is composed of the same base material as the first lens array 120B and the second lens array 130B. That is, the translucent member 126 has a refractive index equal to that of the first lens array 120B and the second lens array 130B. Further, the adhesive 128 for joining the first lens array 120B and the translucent member 126, and the translucent member 126 and the second lens array 130B, respectively, is also refracted substantially equal to the first lens array 120B and the second lens array 130B. Have a rate.

  For this reason, according to the projector 1004 according to the third embodiment, it is possible to further suppress the reflection of light at the interface between each of the first lens array 120B and the second lens array 130B and the translucent member 126. The loss of light quantity due to such undesirable reflections can be further reduced.

  In the projector 1004 according to the third embodiment, the translucent member 126 has the same linear expansion coefficient as that of the first lens array 120B and the second lens array 130B.

  For this reason, according to the projector 1004 according to the third embodiment, it is possible to suppress the generation of thermal stress accompanying the temperature change due to the use of the projector, and thus the first lens array 120B and the second lens array 130B and the translucent light are transmitted. It becomes possible to suppress damage at the joint portion with the member 126.

[Embodiment 4]
FIG. 6 is a diagram illustrating an optical system of the projector 1006 according to the fourth embodiment. In FIG. 6, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the projector 1006 according to the fourth embodiment has basically the same configuration as the projector 1000 according to the first embodiment, but includes the first optical lens and the second optical lens. The configuration is different from that of the projector 1000 according to the first embodiment.

  That is, in the projector 1000 according to the first embodiment, the first optical lens 170 and the second optical lens 180 have the same shape, whereas in the projector 1006 according to the fourth embodiment, the first optical lens 170 and the second optical lens 180 have the same shape. The optical lens 170A and the second optical lens 180A have different shapes. Specifically, the power of the first optical lens 170A disposed in the optical path through which relatively long wavelength color light (that is, red light) passes is relatively short wavelength color light (that is, blue light) passes. The lens is designed to be larger than the power of the second optical lens 180A disposed in the optical path.

In general, the refractive index of a lens has wavelength dispersion characteristics, and the refractive index of light having a relatively long wavelength is smaller than the refractive index of light having a relatively short wavelength. For this reason, since light having a relatively long wavelength is less refracted than light having a relatively short wavelength, if the powers of the first optical lens and the second optical lens are set to be the same, a relatively long wavelength is used. The size of the illumination area irradiated on the image forming area is likely to be different between the case where the light of the incident light and the light of a relatively short wavelength are incident.
However, in such a case, according to the projector 1006 according to the fourth embodiment, the red light passes through the first optical lens 170A having higher power (higher refractive power) than the second optical lens 180A. Therefore, the difficulty of refracting red light with respect to green light is compensated, and the image forming area is irradiated when light having a relatively long wavelength is incident and light having a relatively short wavelength is incident. It becomes possible to make the sizes of the illuminated areas the same.
For this reason, an illumination area of the same size is formed for each electro-optic modulation device 400R, 400G, 400B corresponding to each color light, the illumination state for each color light becomes uniform, color unevenness is reduced, and color Reproducibility is improved.

  The projector manufacturing method according to the fourth embodiment is a method for manufacturing the projector 1006 described above, and a step of preparing a plurality of types of first optical lenses having different focal lengths as the first optical lens 170A. Then, as the second optical lens 180A, a step of preparing a plurality of types of second optical lenses having different focal lengths and a plurality of types of first optical lenses having different focal lengths are selected and arranged. Alternatively, by disposing any of the plurality of types of first optical lenses having different focal lengths, the size of the illumination area of the light emitted from the first superimposing optical system can be changed to the image of the first electro-optic modulation device 400R. The step of adjusting the focal length of the first superimposing optical system so as to match the size of the formation region and any of a plurality of types of second optical lenses having different focal lengths Or by disposing any of a plurality of types of second optical lenses having different focal lengths, the size of the illumination area of the light emitted from the second superimposing optical system Adjusting the focal length of the second superimposing optical system so as to match the size of the image forming area of the optical modulation device 400G and / or the third electro-optic modulation device 400B.

  Specifically, first, as the first optical lens 170A and the second optical lens 180A described above, a plurality of types of first optical lenses and second optical lenses having different focal lengths are prepared.

  Next, while confirming the size of the illumination area L in the image forming area S of the electro-optic modulation device 400R, an appropriate one as the first optical lens 170A is selected from the prepared first optical lenses. Deploy. In the case where the size of the illumination area L is suitable for the size of the image forming area S of the electro-optic modulation device 400R without the first optical lens 170A being arranged, the first optical lens is used. It is not necessary to arrange the lens 170A.

  Similarly to the case of the first optical lens 170A, the second optical lens 180A is prepared while confirming the size of the illumination area L in the image forming area S of the electro-optic modulation devices 400G and 400B. Among these optical lenses, a suitable second optical lens 180A is selected and arranged. In the case where the size of the illumination area L is suitable for the size of the image forming area S of the electro-optic modulators 400G and 400B without arranging the second optical lens 180A, the second area is used. It is not necessary to arrange the optical lens 180A.

  For this reason, according to the method for manufacturing a projector according to the fourth embodiment, as in the case of the method for manufacturing a projector according to the first embodiment, it is possible to easily adjust the size of the illumination area, or electro-optic modulation. Even if the size of the apparatus is changed, it is an excellent manufacturing method capable of manufacturing a projector that can use the illumination optical system before changing the electro-optic modulator.

[Embodiment 5]
FIG. 7 is a diagram showing an optical system of the projector 1008 according to the fifth embodiment. In FIG. 7, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the projector 1008 according to the fifth embodiment has basically the same configuration as the projector 1000 according to the first embodiment, but further includes a superimposing lens fixing device. This is different from the projector 1000 according to the first embodiment.

  The projector 1008 according to the fifth embodiment further includes a superimposing lens fixing device 162 for removably fixing the superimposing lens 160 to the optical element housing case 10.

  For this reason, according to the projector 1008 according to the fifth embodiment, since the superimposing lens 160 itself can be exchanged, the size of the illumination area can be significantly adjusted. As a result, the projector 1008 according to the fifth embodiment is particularly suitable for changing the size of the electro-optic modulation device. In this case, the same color separation light guide optical system can be used by appropriately changing the first optical lens and the second optical lens.

  The projector of the present invention has been described based on each of the above embodiments. However, the present invention is not limited to each of the above embodiments, and can be implemented in various modes without departing from the scope of the invention. For example, the following modifications are possible.

  (1) In the projectors 1000 to 1008 of the above-described embodiments, the case where the first optical lens and the second optical lens are respectively arranged at predetermined positions in the optical path in order to adjust the size of the illumination area is illustrated. However, the present invention is not limited to this. If necessary, only the first optical lens may be disposed, or only the second optical lens may be disposed. Further, when there is no need to adjust the size of the illumination area, the first optical lens and the second optical lens may not be arranged.

  (2) In the projectors 1000 to 1008 of the above embodiments, the convex meniscus lens disposed with the convex surface facing the light incident side is used as the optical lens. However, the present invention is not limited to this. In addition, an optimal optical lens can be used in combination with a superimposing lens. For example, a composite lens composed of two or more lenses can be suitably used.

(3) In the projector manufacturing method according to each of the above embodiments, the step of preparing a plurality of types of optical lenses having different focal lengths as the optical lens, and the size of the illumination area of the light emitted from the superimposing optical system are electro-optics. Including adjusting the focal length of the superimposing optical system so as to match the size of the image forming area of the modulation device, but the present invention is not limited to this. If the size of the illumination area must be changed significantly, such as when changing the size of the image forming area of the electro-optic modulator, the lens is used as a superposition lens before the step of adjusting the focal length of the superposition optical system. A superimposing lens by preparing a plurality of superimposing lenses having substantially the same focal position and different focal lengths, and selecting and arranging any of the superimposing lenses from a plurality of superimposing lenses having different focal lengths. And further adjusting the focal length of the superimposing optical system so that the size of the illumination area of the light emitted from the superposed optical system matches the size of the image forming area of the electro-optic modulator. In the step of adjusting the distance, the focal length of the superimposing optical system is finely adjusted so that the size of the illumination area of the light emitted from the superimposing optical system matches the size of the image forming area of the electro-optic modulator. Door is preferable.
By adopting such a method, even if the size of the electro-optic modulator is significantly changed, the size of the illumination area generated by the superimposing optical system is greatly increased by exchanging the superimposing lens together with the optical lens. Since the size of the illumination area can be finely adjusted by the optical lens, the illumination optical system before the change of the electro-optic modulation device can be used as it is.
(4) The projectors 1000 to 1008 of the above embodiments are so-called three-plate projectors including three electro-optic modulation devices, but the present invention is not limited to this, and one, two, or four The present invention can also be applied to a projector including at least one electro-optic modulation device. That is, the present invention can be applied to a projector including a superimposing optical system that divides light from a light source device into a plurality of partial light beams and superimposes the divided partial light beams in an illuminated area.
(5) The projectors 1000 to 1008 of the above embodiments are transmissive projectors, but are not limited thereto. The present invention can also be applied to a reflection type projector. Here, the “transmission type” means that the electro-optic modulation device as the light modulation means, such as a transmission type electro-optic modulation device, is a type that transmits light. Means that the electro-optic modulation device as the light modulation means is a type that reflects light like the reflection type electro-optic modulation device. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

  (6) Although the projectors 1000 to 1008 of the above embodiments use an electro-optic modulation device using a liquid crystal panel as the electro-optic modulation device, the present invention is not limited to this. In general, the electro-optic modulation device may be any device that modulates incident light according to image information, and a micromirror light modulation device or the like may be used. For example, a DMD (digital micromirror device) (trademark of TI) can be used as the micromirror light modulator.

  (7) The projectors 1000 to 1008 of the above-described embodiments are reflected by the ellipsoidal reflector 114, the arc tube 112 having the emission center near the first focal point of the ellipsoidal reflector 114, and the ellipsoidal reflector 114 as the light source device 110. Although the light source device having the concave lens 118 that emits the focused light toward the first lens array 120 is used, the present invention is not limited to this, and the parabolic reflector and the parabolic reflector A light source device having an arc tube having a light emission center near the focal point can also be preferably used.

  (8) In addition, the present invention can be applied to a front projection projector that projects from the side that observes the projected image and a rear projection projector that projects from the side opposite to the side that observes the projected image. Not too long.

FIG. 3 shows an optical system of the projector 1000 according to the first embodiment. FIG. 3 is a diagram for explaining the effect of the projector 1000 according to the first embodiment. FIG. 6 is a diagram for explaining an effect of a projector 1000a according to a modification of the first embodiment. FIG. 6 is a diagram showing an optical system of a projector 1002 according to a second embodiment. FIG. 10 shows an optical system of a projector 1004 according to a third embodiment. FIG. 10 shows an optical system of a projector 1006 according to a fourth embodiment. FIG. 10 shows an optical system of a projector 1008 according to a fifth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Optical element housing | casing, 110 ... Light source device, 112 ... Light emission tube, 114 ... Ellipsoidal reflector, 116 ... Auxiliary mirror, 118 ... Concave lens, 120, 120A, 120B ... 1st lens array, 121, 121A, 121B ... 1st small lens, 122, 124 ... Lens array unit, 126 ... Translucent member, 128 ... Adhesive, 130, 130A, 130B ... 2nd lens array, 131, 131A, 131B ... 2nd small lens, 140 ... Polarized light Conversion element, 150, 150A ... superimposing optical system, 160 ... superimposing lens, 162 ... superimposing lens fixing device, 170, 170A, 170a ... first optical lens, 172 ... first optical lens fixing device, 180, 180A ... first 2 optical lens, 182... Second optical lens fixing device, 200... Color separation light guiding optical system, 210. Ic mirror, 220 ... second dichroic mirror, 230, 240, 250 ... reflecting mirror, 260 ... incident side lens, 270 ... relay lens, 300R, 300G, 300B ... condensing lens, 400R, 400G, 400B ... first to first 3, electro-optic modulation device, 500 ... cross dichroic prism, 600 ... projection optical system, 1000, 1002, 1004, 1006, 1008 ... projector, f ₁ ... focal length of second small lens, f ₂ ... focal length of superimposing lens , F ₃ , f ₄ ... focal length of superimposing optical system, L ... illumination region, S ... image forming region, SCR ... screen.

Claims (13)

A light source device for emitting an illumination light beam;
A first lens array having a plurality of first small lenses for dividing an illumination light beam from the light source device into a plurality of partial light beams;
A second lens array having a plurality of second small lenses corresponding to the plurality of first small lenses;
A superimposing lens for superimposing the partial light beams from the second lens array on the illuminated area;
An electro-optic modulator that modulates light superimposed by the superimposing lens according to image information;
A projector comprising: a projection optical system that projects light modulated by the electro-optic modulation device;
An optical lens disposed in an optical path between the superimposing lens and the electro-optic modulator,
The focal length of the superimposing optical system composed of the superimposing lens and the optical lens is different from the focal length of only the superimposing lens,
The projector according to claim 1, wherein a focal position of the superimposing optical system including the superimposing lens and the optical lens is the same as a focal position of only the superimposing lens . The projector according to claim 1, wherein
A first dichroic mirror that separates light from the superimposing lens into first color light, second color light, and third color light, and second color light and third color light from the first dichroic mirror are second. A color separation light guiding optical system having a second dichroic mirror that separates the color light into the third color light, and
As the electro-optic modulation device, a first electro-optic modulation device to a third electro-optic modulation device for modulating the first color light to the third color light, respectively,
A color synthesizing optical system that synthesizes the color lights modulated by the first electro-optic modulation device to the third electro-optic modulation device and emits them to the projection optical system;
As the optical lens, a first optical lens disposed between the first dichroic mirror and the first electro-optic modulation device, and disposed between the first dichroic mirror and the second dichroic mirror. A second optical lens,
The focal length of the first superimposing optical system composed of the superimposing lens and the first optical lens is different from the focal length of only the superimposing lens, and is composed of the superimposing lens and the first optical lens. The focal position of the first superimposing optical system is the same as the focal position of only the superimposing lens,
The focal length of the second superimposing optical system composed of the superimposing lens and the second optical lens is different from the focal length of only the superimposing lens, and is composed of the superimposing lens and the second optical lens. The focal position of the second superimposing optical system is the same as the focal position of only the superimposing lens . The projector according to claim 2,
At least one of the first optical lens and the second optical lens is a convex meniscus lens. The projector according to claim 2,
At least one of the first optical lens and the second optical lens is a compound lens including two or more lenses. The projector according to claim 2,
The projector according to claim 1, wherein the first optical lens and the second optical lens have the same shape. The projector according to claim 2,
Of the first optical lens and the second optical lens, the power of the lens arranged in the optical path through which the relatively long wavelength colored light passes is arranged in the optical path through which the relatively short wavelength colored light passes. A projector characterized by being larger than the power of the lens. In the projector according to any one of claims 1 to 6,
The projector according to claim 1, wherein the first lens array and the second lens array are integrated. In the projector according to any one of claims 1 to 6,
A light transmissive member for guiding light from the first lens array to the second lens array is provided between the first lens array and the second lens array, and the first lens array and the second lens array A projector, wherein a lens array is joined via the translucent member. In the projector according to any one of claims 1 to 8,
The light source device includes an ellipsoidal reflector, an arc tube having a light emission center in the vicinity of a first focal point of the ellipsoidal reflector, and a concave lens that emits focused light reflected by the ellipsoidal reflector toward the first lens array. A projector comprising: The projector according to claim 9, wherein
The projector according to claim 1, wherein the arc tube is provided with reflecting means for reflecting light emitted from the arc tube toward the illuminated area toward the ellipsoidal reflector. A light source device for emitting an illumination light beam;
A first lens array having a plurality of first small lenses for dividing an illumination light beam from the light source device into a plurality of partial light beams;
A second lens array having a plurality of second small lenses corresponding to the plurality of first small lenses;
A superimposing lens for superimposing the partial light beams from the second lens array on the illuminated area;
An electro-optic modulator that modulates light superimposed by the superimposing lens according to image information;
A projector manufacturing method comprising: a projection optical system that projects light modulated by the electro-optic modulation device,
An optical system that forms a superimposing optical system together with the superimposing lens, the focal length of the superimposing lens is different from the focal length of the superimposing optical system, and the focal position of the superimposing lens and the focal position of the superimposing optical system are the same. Preparing a plurality of types of optical lenses having different focal lengths as lenses;
Light emitted from the superimposing optical system by selecting one of a plurality of types of optical lenses having different focal lengths or arranging none of the plurality of types of optical lenses having different focal lengths Adjusting the focal length of the superimposing optical system so that the size of the illumination area matches the size of the image forming area of the electro-optic modulation device. In the manufacturing method of the projector of Claim 11,
Before the step of adjusting the focal length of the superimposing optical system,
Preparing a plurality of types of superimposing lenses having substantially the same focal position and different focal lengths as the superimposing lens;
The size of the illumination area of the light emitted from the superimposing lens is selected from the plurality of superimposing lenses having different focal lengths as the superimposing lens, and the image of the electro-optic modulation device is obtained. Coarsely adjusting the focal length of the superimposing optical system so as to match the size of the formation region,
The step of adjusting the focal length of the superimposing optical system includes the superimposing optical system so that the size of the illumination area of the light emitted from the superimposing optical system matches the size of the image forming area of the electro-optic modulation device. A method for manufacturing a projector, characterized by finely adjusting a focal length of a system. In the manufacturing method of the projector of Claim 11 or Claim 12,
The projector separates light from the superimposing lens into first color light, second color light, and third color light, and second color light and third color light from the first dichroic mirror. A color separation light guide optical system having a second dichroic mirror that separates the first color light and the third color light, and a first color light to third color light as the electro-optic modulation device, respectively. Color combining that combines the color lights modulated by the first electro-optic modulation device to the third electro-optic modulation device and the first electro-optic modulation device to the third electro-optic modulation device and emits them to the projection optical system A projector comprising an optical system,
As a step of preparing a plurality of types of optical lenses having different focal lengths,
The superimposing lens constitutes a first superimposing optical system, the focal length of the superimposing lens and the focal length of the superimposing optical system are different, and the focal position of the superimposing lens and the focal position of the first superimposing optical system Preparing a plurality of types of first optical lenses having different focal lengths as first optical lenses that are identical to each other;
The superimposing lens constitutes a second superimposing optical system, the focal length of the superimposing lens and the focal length of the superimposing optical system are different, and the focal position of the superimposing lens and the focal position of the first superimposing optical system And preparing a plurality of types of second optical lenses having different focal lengths as the second optical lens to be the same ,
As a step of adjusting the focal length of the superimposing optical system,
By selecting any one of the plurality of types of first optical lenses having different focal lengths or arranging none of the plurality of types of first optical lenses having different focal lengths, the first The focal length of the first superimposing optical system is adjusted so that the size of the illumination area of light emitted from the superimposing optical system matches the size of the image forming area of the first electro-optic modulator. Process,
By selecting any one of a plurality of types of second optical lenses having different focal lengths or disposing any of the plurality of types of second optical lenses having different focal lengths, the second The size of the illumination area of light emitted from the superimposing optical system is adapted to the size of the image forming area of the second electro-optic modulator and / or the third electro-optic modulator. And adjusting the focal length of the superimposing optical system.